1. Field of the Invention
This invention relates to an input element such as a panel switch having good outward appearance as well as high quality.
2. Description of the Prior Art
Panel switches have been used in recent years in combination with a display picture being output from a computer. For example, by superposing a panel switch on a display picture, when a certain letter, figure or pattern is touched with a finger tip, the touched portion is connected electrically, whereby the signal from an external circuit can be displayed on the display picture.
Such a panel switch is constituted of a pair of transparent substrates of which at least one is flexible, each having electrodes of transparent electroconductive film on its surface, and being arranged in confrontation with the electrode-carrying surfaces facing each other and with a space therebetween, and a spacer is arranged at the peripheral portions of said pair of substrates to hold said space, the respective film electrodes provided on one transparent substrate being connected to an external circuit. As the transparent substrate, glass or plastics have been employed, and as the transparent electroconductive film, indium oxide (In.sub.2 O.sub.3) film, tin oxide (SnO.sub.2) film (NESA film) or indium oxide film containing about 5 wt. % of tin oxide (ITO film) has been employed. When one surface of this panel switch is touched with a finger tip, the upper and lower electroconductive films at the touched portion are connected to each other, thereby informing the external circuit of the position touched by the finger tip.
In the panel switch of the prior art for prevention of malfunctioning caused by contact between a pair of electroconductive films while the switch is not actuated tension is applied on the upper substrate and such tension is received by the peripheral spacer and the adhesive. However, in such a panel switch, the upper substrate may be elongated due to changes in temperature or humidity to result in the diminished effect of the tension applied on the upper substrate, whereby contact may occur between the electroconductive films of the upper and lower substrates during its non-use.